Marine Ranching Area Research Articles

음향 텔레메트리 기법에 의한 인공어초 지역에서의 조피볼락의 이동범위 및 일주행동 측정

The movement ranges and diurnal behavior of the rockfish (Sebastes schlegeli) sonic tagged externally were measured by the acoustic telemetry in the marine ranching area of Tongyoung on 20 to 26 March and 4 October to 3 November, 2003. The results of study are as follows: 1. Two cage cultured fishes (body length: ) were released the point where located approximately from the caught point on 30 March, 2003. They moved to the south away Sojangdudo and stayed within a radius of the position during the study. 2. Three wild fishes (body length: ) were released around the caught point on 4 and 8 October, 2003. It was often measured that tagged fishes moved out the radius of released point for a week after release. After several days, the movement range tended to be reduced. Finally, they stayed within the radius of released point. 3. There was no significant difference of diurnal behavior of the rockfish between the cage cultured and the wild fishes. The movement range, however, for the night-time was a little wider than for the day-time.

어군탐지기를 이용한 인공어초 주변의 어군량 추정

The hydro-acoustic method is widely used for estimating biomass and distribution of fisheries resources along the coast and in the ocean. High costs and time are necessary to construct systems for this method and to initially educate specialists. It has been used in fisheries of advanced nations like Japan and Norway, because it is more efficient than other methods. In order to research the behavior of fish around an artificial reef using an echo sounder, volume backscattering strength (SV) and fish per cubic meter (FPCM) of darkbanded rockfish around the model artificial reef in a water tank were measured. Moreover, behavior of fish was observed in an adjacent artificial reef, which was constructed at Tongyeong marine ranching area. Following that, an acoustics survey was conducted at Mirukdo around the Tongyeong marine ranching area, in order to understand the spatial distribution and strength of fisheries resources. Very high patches of fish were found in a wide area around the artificial reef. It is thought that an approaching fish school around the artificial reef can be measured accurately by using an echo sounder of high resolution. Moreover, use of other monitoring methods like of diving or ROV simultaneous with an echo sounder is required in order to grasp the species and ecology of fish inhabiting the area around the artificial reef.